Goodwill & Other Intangibles Gross carrying amount and related accumulated amortization of definite-lived intangible assets (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Gross	$ 13,219	$ 4,860	$ 4,833
Accumulated Amortization	(3,807)	(3,275)	(2,648)
Net	9,412	1,585	2,185
Existing Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	7,500	3,200	3,200
Accumulated Amortization	(2,637)	(2,159)	(1,681)
Net	4,863	1,041	1,519
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	3,494	234	234
Accumulated Amortization	(155)	(128)	(99)
Net	3,339	106	135
Other Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	2,225	1,426	1,399
Accumulated Amortization	(1,015)	(988)	(868)
Net	$ 1,210	$ 438	$ 531